After you you reached Snowpoint City and beaten the Galactics, you go to the Disortion World and catch or make Giratina faint, you can go to Sunnyshore City.
sunnyshore
you surf
you can get it before you get to sunnyshore city
You need to battle Girtina in the Reverse \World then you will be able to go to Sunnyshore
in sunnyshore
i believe you get it in veilstone or sunnyshore
sunnyshore city
Sunnyshore City.Defeat Volkner first...
In A Grass Patch Close To Sunnyshore City.
at the front of sunnyshore city
on the left of sunnyshore city. a fisherman has feebas
first you you have to catch Giratina